The ultimate goal is a basic understanding of the many factors regulating or influencing intraocular pressure. Emphasis has been plced on the primate since it is felt that findings will be more likely applicable to human ocular physiology. Studies are directed at determining the effect of prostaglandins on intraocular pressure, outflow facility including pseudofacility, pupil size, and aqueous humor protein content. The interaction between prostaglandins and autonomic and cholinerEic drugs will also be investigated. Studies also will be made on a colony of rabbits with buphthalmos (glaucoma), emphasis being placed on the pathophysiology as it relates to aqueous humor dynamics.